Bearing.



E. P, W. ALEXANDERSON.

' BEARING.

APPLICATION IILED DEG. 'l, 1912.

Patented Sept. 8,1914,

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Inventor-r I Ernst FT Wafilexanderson 6 s WWI- a i.

Withesses g I UNITED STATES PATENT-(DEFICE.

Eims'r I. w. nLnxANDEBsoN, 0F 'scnnirnornnx, saw Yong, assmnon 'roGENERAL' ELECTRIC comrsiw, A CORPORATION ornnwxonx.

B ARING.

To all whom it may concern I Be. it known that I, ERNST F2 W. ALEX-ANDERSON, a citizen of the United States, re siding at Schenectady,county of Schenectady, State of New York, have invented c'ertain new anduseful Improvements in Bear: ings, of which the following'is aspecification. My invention relates to bearings, and is particularlyapplicable to bearings in ma chines of the type disclosed in Patent, No.1,008,577, issued to me. Y

My present application is a division of my application for highfrequency alternators Serial No. 655,480, filed October 19, 1911.

The present invention consists in a novel construction ofyielding-bearing, which will be best understood by reference to' the.accompanying drawings, in which v Figure 1 is a side elevation of amachine embodying the novel features of my present invention; Fig. 2 isa detail view incross section showing the self alining construction ofthe bearings; Fig. 3'is a sectional view taken on line 3-3 of Fig. 2;Fig. 4 is asectional view taken on line 14 of Fig.1,

and Fig. 5 is a detail view in cross section illustrating theconstruction of the inner.

bearings.

The machine illustrated in the drawings is an alternator of the generalconstruction described in my prior patent, and comprises a stator 5supported by a base 6. The rotor; of the alternator is carried at: thecenter'of a long flexible shaft'7, as shown in Fig. 1. The purpose ofsuch a shaft is to allow the rotor or inductor, when up to speed, torevolve about'its own center of gravity. The

main bearings 8 are at a distance from the rotor or center of theshaft'so as to permit the shaft to bend and the rotor to center itselfon its own center of gravity when up to speed- Other bearings9are'placed near the rotor or center of ztlge shaft. vThese bearings arenormally oiifi-fof engagement with the shaft, but are engaged by theshaft when the rotor vibrates'when passing its critical speed-in comingup tospeed. -At this time these bearings 9 serve to prevent suchexcessive vibration as might brin'g the periphery of the rotor intoengagement with the stator.

- The construction of the bearings 9 will be understood by referencetoFig. 5 of the thre'a' Specification of Letters atcnt.' Patented Sept. 8,1914. Original application filed October 19, 1911, Serial No. 655,480.Divided and this application filed December 7. 1913. Serial No. 735,358.

drawings. Each bearing 9 has screw threaded intb it a member 21, whichsurrounds the shaft 7 so loosely that during normal runningit is notengaged by the shaft, but, during the vibration that occurswhile therotor is being brought up to speed and is passing its critical speed,the member .21'is engaged by the shaft 7 and serves to limit thevibration of the rotor. At the same time the member 21 serves as an enda thrust bearing for the rotor. A washer 22 is fast to the shaft? androtates with the shaft and lock nuts 26, the latterv being-screwthreaded on the shaft and serv'ng to prevent axial displacement ofthe'ro or on the shaft. A s'tati0nary member 23 has a bearing engagementwith the washer'22. 011 1st supplied to the bearing surfaces throughholes 24. The member 21 is screw ed into the bearing 9 in order to permitz-its' axial -adjustment and the proper division'flof end-thru'stbetween the bearings.

member 21 in pos tion.

In order to obtain good efliciency in a machine of this character, theair gaps should besmalLand-since the air gaps of the machine liein'lradial planes, it is necessary to prevent axiaLd-isplacement of therotor in.

running. The ajrrangleme'nt of bearings deabove', if" t siti ucted asshown and; explained in detail in my pri'or patent and as illustrated inFig. 2

of this application, s'erve'to maintain the roe. bearings are con-1 Alook nut 25 is provided for securing the tor in its proper positionmidway between. the faces of the stator, and thus the air gaps may bemade small.

The member 10' the usual self alining construction provided with theusual pin 11. The rotatable shaft .7, where 'it passes through thebearing, is grooved as shown, and between it and" the of each bearing 8is of member 10 is a cylindrical member 12. The

member 12 is grooved on its innerside to fit the grooves in the shaft 7,so that it to speed';'- The member 12 isv slotted and pierced with holesto receive oil which may both supports the weight of the shaft and besupplied to the bearings 8 by pipes 13. As is clearly shown in Fig. 2,the oil is fed freely to the entire contact surface between the shaft 7and the member 12. It will thus'be seen that both bearings on each sideof the rotor are designed to receive an end thrust of the shalt, and ifin operation the rotor gets slightly out of center, there is producedmagnetically, because one is then smaller than the other, a pull tendingto move the rotor axially farther from its midway position.

This resultsin increased pressure on the two thrustbearingsbn one. sideof the rotor and consequently a greater generation of heat in thesehearings. This increased heat produces a relative eapansion oi thelength of the shaft between the twohearings on that side of the rotor,and this expansion serves to restore the inductor to its midwayposition. The centering is thus entirely automatic.

My present invention comprises a novel feature in regard to the supporttor the outer bearings 8.- it will he clearly seen that the constructionoi the hearingssdis such that these bearings normally tend to limit alongitudinal movement of the ln order to prevent any possibility of himmg upon a longitudinal expansion oil the shath throughout its length,caused for enample, by a temperature rise, ll pivotally support thebearings 8 so that; 'diey yield under the torce ct longitudinalexpansion of the shalt. To give the bearings this yielding support theirpillow blocks Mt are mounted pivotally on roller bearings so that thetops of the pillow hloclrs where the shaft bearingniembers are carriedcan'move a small amount in direction of the axis of the shalt. Theroller bearing for each pillow bloclr consists of a cylindrical rod 15which engages a ll-shaped groove in the base 6 and a similar groove inthe base oi the pillow block, as will be readily seen by reference toFigs. 1 and t oi the drawings. Each pillow block is thus mounted forangular movement about its cooperating rod 15 as a pivot. in order toinsure that both bearings 8 shall move equally so as to maintain therotor central, the pillow hloclrs are connected by beams 16 and a Hatspring? 1?. This yields to permitthe upward or downward movement oi theadjacent inner ends of beams 16 as the bearings move under the expansionor contraction of the shaft, but prevents movement of either beam unlessthe other beam moves equally, thus an equal and corresponding movementof both hearings 8 is insured. In this manner a thrust upon one bearingis transmitted through the beams and connecting spring to produce acorresponding and equal thrust on the other bearing. The movement of thehearings 8 is at most only a small fraction of an inch and with the selfalining construction of bearings this movement does not afi'ect the truealinement of the shaft and hearings or cause the shaft to bind in thebearings.

The movement of the pillow blocks in any direction except that of theaxis of the shaft, is prevented by dowel pins 18 which are jointed asindicated in Fig. t to permit the axial movement of the bearings, butwhich prevent movement in any other direction. Bolts 19, which arescrewed into a bed plate and which press against the pillow blocks, orrather against the beams 16 secured to the pillow blocks, throughcompression springs 20, hold the pillow blocks firmly pressed on theroller hearings 15, but permit the desired slight movement of the pillowblocks on these hearings.

The operation or the bearings, 8 and cooperatively relatedelements willbe understood from the toregoi description and following explanation.sch hearing can turnthrough a slight angle due to the piv otal mountingct the'pillow blocks it, the pillow blocks turning about the rods 15 aspivots. Assuming that the right hand bearing 8 receives a thrust TlOllllthe shaft its supporting pillow block will turn through a small angleabout the cooperating rod 15 as a pivot. The right hand beam 7' l6willturn with the pillow block and theinner end or the beam will moveupwardlya certain amount. The inner ends of the beams 16 are flexiblysecured together by means of the spring 1'? and thus when the pillowblocks, a beam cannot move without .1

moving its pillow block. Thus when the inner end or the left hand beamis slightly raised by the right hand beam, the left hand pillow block isslightly turned about its pivot. The resultant 'olf these 1 diderentmovements is that the two pillow blocks and hence the two bearings 8 aremoved about their pivots in opposite directions an equal amount i Whileit have described my invention, with reference to dynamo electricmachines, it is obvious that the invention is iu no sense limited tosuch machines, but adapted to be employed in machines of any characterwhere the bearings normally tend 'to limit longitudinal movement of theshaft.

are within the by Letters Patent of the United States, is

1. In combination a. rotatable shaft operatively mounted between twosupporting bearings, a rotor member secured to said shaft between saidbearings, each of said bearings tending normally to limit longitudinalmovement of the shaft but being mounted to yield under a longitudinalexpansion of the shaft, and means whereby upon the longitudinalexpansion of the shaft a thrust on one bearing is transmitted to producea corresponding thrust on the other bearing.

2. In combination a rotatable shaft operatively mounted between twosupporting bearings, a rotor member secured to said shaft between saidbearings, a pivotally mounted pillow block for each bearing whereby thebearing can be moved'through a small angle, a beam rigidly secured toeach pillow block, and means for yieldingly connecting said beams toeach other.

8. In combination a rotatable shaft operatively mounted between twosupporting bearings, a movably mounted pillow block for each bearing, abeam secured to each pillow block, said beams extending from the pillowblocks toward each other, and means i for yieldingly connecting theadjacent ends ofsaid beams.

4. In combination arotatable shaft operatively mounted between twosupporting bearings, each of said bearings tending normally to limitlongitudinal movement of the shaft, means for mounting said bearings soas to permit a longitudinal expansion of the shaft, beams secured toeach bearing and extending toward each other, and means for yieldinglyconnecting the adjacent ends of said beams.

5. In combination a rotatable shaft operatively mounted between twosupporting bearings, a rotor member secured to said shaft between saidbearings, each bearing comprising a pillow block and a self-aliningbearing member operatively carried thereby, means for pivotally mountingeach pillow block whereby it yields under a lon-' gitudinal thrust ofthe shaft, and means whereby a movement of one pillow block istransmitted to produce a corresponding movement of the other pillowblock.

6. In combination a rotatable shaft operativcly mounted between twosupporting and extending toward each other, and means yieldinglyconnecting the adjacent ends of said beams. j

7 In combination a rotatable shaft opertively mounted between two thrustbearings, means in addition to said bearings for limiting longitudinalmovement of the shaft, each of said bearings being mounted to yieldunder a longitudinal thrust of the shaft, and means whereby alongitudinal thrust'on one bearing is transmitted to produce acorresponding thrust on the other bearing.-

8. In combination a rotatable shaft operatively mounted between two.thrust bearings, means in addition to said bearings for l'mitinglongitudinal movement of the shaft, a pillow block for each bearingmounted to yield under a longitudinal thrust of the shaft, beams securedto each pillowv block and extending toward each other, and meansyieldingly connecting the adjacent ends of said beams.

9. The combination with a rotatable shaft of bearings for said shaft,said bearings comprising a movably mounted pillow block and a selfalining bearingnember,-beams secured to each pillow block and extendingtoward each other, and a leaf spring connecting the adjacent ends ofsaid beams.

10. The combination with a long flexible rotatable shaft of fourbearings, two on each side of the center of said shaft, one bearing theother at a distance therefrom, the two outer hearings on opposite sidesof the center being yieldingly mounted to permit lon gitudinal expansionof the shaft, and connecting means between said last mentioned bearingsfor insuring equal movement of such bearings upon the longitudinalexpansion of the shaft.

11. The combination with a long flexible rotatable shaft of fourbearings, two on each side of the center of said shaft, one bearing oneach side of the center of said shaft being comparatively close to thecenter and the other at a distance therefrom, each of the two outerhearings on opposite sides of the center comprising a movably mountedpillow block and a self alining hearing-member, beams secured to eachpillowblock of the last mentioned bearings and extending toward eachother, and means for yieldingly connecting the adjacent ends of saidbeams.

In witness whereof I hereunto set my hand this 5th day of December,1912.

ERNST F. W. ALEXANDERSON.

lVitnesses:

BENJAMIN B. HULL, HELEN ORFORD.

